Fat-to-Muscle Ratio Shows No Clear Link to Cognitive Impairment in Older Adults

A cross-sectional study of community-dwelling adults aged 65 and older in Shenzhen, China, found no significant association between the fat-to-muscle ratio (FMR) and cognitive impairment as defined by the Montreal Cognitive Assessment (MoCA). The research, published in BMC Geriatrics, examined whether an imbalance between adiposity and muscle mass, captured by a single ratio, relates to cognitive impairment in older adults. In the fully adjusted primary analysis, each one-standard-deviation increase in total FMR was associated with an odds ratio of 1.203 (95% CI: 0.957–1.511) for MoCA-defined cognitive impairment in the overall sample, an interval that includes the null value of 1. Regional FMR measures for the trunk, legs, and arms were likewise not significantly associated with the outcome in the overall sample.

The study enrolled adults aged 65 years or older registered at community health service centers in Nanshan District, Shenzhen. The prevalence of MoCA-defined cognitive impairment in the sample was 47.93%. The primary analysis used multivariable logistic regression to test the association between total FMR and cognitive impairment. Beyond this primary test, the researchers conducted a set of exploratory analyses covering regional FMR measures, sex-stratified subgroups, seven cognitive domains, and indirect effects through blood lipid markers. To guard against false positives across this large number of tests, the authors applied the Benjamini–Hochberg false discovery rate (FDR) procedure separately within three testing families: four fully adjusted logistic-regression tests for total, trunk, leg, and arm FMR; 28 cognitive-domain tests (four FMR measures across seven domains); and 12 lipid indirect-effect tests (four lipid markers across three models). FDR correction was performed separately for the overall sample and for the male and female subgroups.

The exploratory sex-stratified analyses produced the most notable nominal findings. Among women, each one-standard-deviation increase in total FMR was associated with higher odds of MoCA-defined cognitive impairment (OR = 1.350, 95% CI: 1.022–1.782), and the same was true for trunk FMR (OR = 1.335, 95% CI: 1.032–1.726). However, neither result remained statistically significant after FDR correction, with both FDR-adjusted P values reaching 0.068. This means the apparent sex-specific association could plausibly reflect chance given the number of tests performed, and the authors treat it as hypothesis-generating rather than confirmatory.

In the exploratory cognitive-domain analyses, inverse associations between FMR and visuospatial/executive function remained significant after FDR correction, whereas nominal positive associations with attention did not survive correction. Separately, exploratory mediation-style analyses suggested triglyceride (TG)-related indirect associations between FMR and MoCA scores in the overall sample and among women, but these indirect-effect findings did not persist after full adjustment. Taken together, the lipid pathway results remain preliminary and unconfirmed.

The authors conclude that total and regional FMR were not significantly associated with MoCA-defined cognitive impairment in the overall sample, and they emphasize that the cognitive-domain and lipid indirect-effect findings are exploratory and require confirmation in prospective studies. Because the study is cross-sectional, it captures a single point in time and cannot establish temporal order or causation between body composition and cognition. The sample was drawn from a single district in one Chinese city, which may limit generalizability to other populations. Readers should also note that the article is being shared early as a peer-reviewed, accepted version that is citable and carries a permanent DOI, but is subject to further edits before the final Version of Record.

Subject of Research: The association between fat-to-muscle ratio and MoCA-defined cognitive impairment in community-dwelling older adults

Article Title: Association of fat-to-muscle ratio with MoCA-defined cognitive impairment in older adults

Article References: Song, Y., Cai, Z., Zhao, D., Ouyang, B., Xu, S., Peng, X., & Zhong, X. (2026). Association of fat-to-muscle ratio with MoCA-defined cognitive impairment in older adults. BMC Geriatrics. https://doi.org/10.1186/s12877-026-08585-2

Image Credits: AI Generated

DOI: 10.1186/s12877-026-08585-2

Keywords: fat-to-muscle ratio, cognitive impairment, MoCA, older adults, cross-sectional study, body composition, visuospatial function, triglycerides, sex differences, false discovery rate, BMC Geriatrics, Shenzhen